1. Field of the Invention
This invention relates to a transmission clutch apparatus which transmits a driving force to a plurality of driving systems within a recording apparatus, and also relates to a recording apparatus which uses the driving force transmission clutch.
2. Description of the Prior Art
Video devices and the like are widely used today, and along with their popularity and development, an apparatus for recording their video images has also been developed. Although there exists various methods for recording images, a so-called thermal recording method is generally utilized. In a thermal recording method, images are recorded by heating recording heads according to image signals. Such a method is advantageous because it reduces the size and cost of the apparatus. When color images are recorded by the thermal recording method, a leading edge of a recording sheet is held by a gripper against a rotary platen which rotates for every color. As the rotary platen is rotated, the recording heads are heated and color images are recorded on the recording sheet. However, in the above recording apparatus, supplying the recording sheet, transporting it to the platen, rolling an ink sheet and so forth have to be carried out either simultaneously or individually. Therefore, electric motors are needed for driving each mechanism which increases the number of parts and makes it difficult to reduce the size of the apparatus.
As an alternative, U.S. Pat. No. 4,268,021 discloses a sheet supply device which drives a platen, a pick-up roller, a transporting roller and a discharging roller with a single step motor. However, in this prior art device an electro-magnetic clutch is used to rotate the pick-up roller and transporting roller independently from the platen, which results in an increased number of parts.